Electrical connector



Aug. 4, 1970" J w. CLEMENTS ELECTRICAL CONNECTOR 2 Sheets-Sheet l FiledJuly 10, 1967 FIGZ FIG]

FIGZA FIGJA INVENTOR JOHN W. CLEMENTS ATTORNEY Aug. 4, 1-970 J. w.CLEMENTS 3,522,484

ELECTRICAL CONNECTOR f 5 LILJL'ILILJULJLILJLJU ITIHHHFIHHHHFIFI I ll 49INVENTOR JOHN W. CLEMENTS ATTORNEY United States Patent 3,522,484ELECTRICAL CONNECTOR John W. Clements, Naperville, Ill., assignor toFlexicon Electronics, Inc. Filed July 10, 1967, Ser. No. 652,216 Int.Cl. 110% 1/04 US. Cl. 317-101 12 Claims ABSTRACT OF THE DISCLOSUREApparatus for connecting flexible flat conductor cables to each other orto one or more circuit cards.

FIELD OF THE INVENTION Electrical connector apparatus.

DESCRIPTION OF THE PRIOR ART Flat multi-conductor cable having flaredend portions to accommodate a plurality of contact areas.

SUMMARY Apparatus for electrically connecting multi-conductored flatcables to the edges of stacked printed circuit cards in which contact isassured by a tension strap. The apparatus also contemplates theelectrical connection of a pair of multi-conductored cables in which theconduc-- tored surfaces are in confronting relation. The electricalconnection has, for its purpose, the supplying of operating voltages andinterconnecting signals or pulse inputs and outputs between variouselectronic apparatus. The present connection is positive and effectiveand eliminates the need for contacts that depend for their effectivenessupon spring action retentivity. Furthermore, the use of the presentconnector facilitates interconnection, modification or repairs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical diagrammatic viewof a connector made in accordance with the present invention shown inthe position it assumes prior to the insertion of electronic circuitcards;

FIG. 1a is a plan view of the connector of FIG. 1;

FIG. 2 is a view similar to FIG. 1 but showing the present connector inthe position it assumes with the circuit cards inserted;

FIG. 2a is a plan view of the connector of FIG. 2;

FIG. 3 is a sectional view taken substantially on line 3-3 of FIG. 2;

FIG. 4 is a fragmentary plan view of one of the circuit cards;

FIG. 5 is an elevational view of an automated programmed modifier stripfor use in modifying the electrical connection between one of theconductored cables and one of the circuit cards;

FIG. 5a is a view of a modified form of a programmed modifier strip;

FIG. 5b is a fragmentary plan view of a circuit card with the contactmodifier strip at FIG. 5 in position; and

FIG. 6 is an enlarged fragmentary sectional view illustrating the use ofmultiple layered circuit cards with the multi-conductored cables andtension strap of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present connector isconstructed and arranged to effect efficient and effective connection ofelectronic circuit cards or module shells containing micro-circuitrypackages and a fiat flexible cable having a plurality of radially spacedconducting paths on the surfaces thereof.

The force necessary for effective conductive contact is a tension forceprovided by exerting a tension force on the tension strap so that theconductive paths of the cable are urged into engagement with theconductive areas of the circuit cards. The resulting contacts of all ofthe circuit cards with the cables are made simultaneously and may bereleased in the same manner, if desired. The present connector obviatesthe need for a connection device which relies upon spring pressure withits concomitant unreliability.

The present invention is directed to improvements in connectors formicro-circuitry and particularly the efficient and effective electricalconnection of semi-conducted integrated micro-circuits and thin film.Prior art connectors for this purpose have been permanent in nature andhave generally involved the use of welding, plating, electro-deposition,soldering, etc. Releasible connectors have been devised to facilitatemaking rapid circuit changes or repairs. This feature is economicallyimportant because of the labor and system down-time failure costs ofpermanent connectors. These releasible connectors generally are of thepin and socket type or other types relying on spring retentivity foreffectiveness. As efforts are made towards increased miniaturizationthere is a tendency to reduce the cross section of the connectors withresultant decrease in strength. Furthermore, there has been a problemwith decreased yield limits for miniaturized electromechanical springcontacts, of copper alloy or the like when the demand is for increasednumerical density of interconnections.

Prior art connectors have been characterized by relatively greatexpense, inherent critical tolerances, and sensitivity to contactmisalignment. The inevitable result of misalignment is a significantquantity of bent or broken contact pins or sockets. Also, even slightlybent pins cause uneven wear on the plated coatings utilized to minimizecorrosion of the contacts, as by oxidation. The accretion of oxidationproducts creates a film on the contact surfaces which is characterizedby high electrical resistance. This results in noise, inadvertentdisconnection, and even rectification.

The spring forces utilized in prior art electrical connectors, whileexhibiting low resistance, require forces for insertion and extricationthat tend to distort spring connectors, thus shortening their usefullives, and also tend to remove valuable plated coatings by abrasion. Theuse of connector plugs in micro-circuitry requires expensive proceduressuch as soldering, welding, wire-wrapping, etc. These plugs increase thecost of the electronic system and defeat the purpose of miniaturization.

The present invention is concerned with connecting flat conductoredcables having a plurality of longitudinally extending transverely spacedconductive paths formed on a dielectric filrn, by etching,electrodeposition or the like. These paths or runs are characterized bylow impedance and low edge capacitance. As a result, these flat cablesshow a substantial reduction in standing waves and electroniccross-talk. The present invention contemplates the electrical connectionof flat conductored cables with other electronic elements, such ascircuit cards, by compressive mating contact forces. The inventioncontemplates the use of tension forces to produce the compressiveforces. Since the exposed flat conductored contacts are a directcontinuum of the parallel spaced flat conductors there is no alterationof line impedances. The nature of the engagement is such that albrasivefriction forces are eliminated and interconnection reliability isenhanced.

Referring now to the drawings and more particularly to FIGS. 1 and 2,the connector of the present invention is indicated generally byreference numeral 10 and includes a housing 12 having at one sidethereof an opening 14 for reception of a module 16 on which is mounted aplurality of spaced circuit cards 18. Within chamber 20, defined by thehousing 10, are a plurality of circuit cards 21 maintained in the spacedrelationship illustrated by means of channel-shaped brackets 22, seeFIG. 3. The circuit cards 18 are arranged in spaced relation in themodule 16 by means of channel-shaped brackets 24, also as shown in FIG.3. A plug 26 is mounted in one wall of the housing 10 and to this plugis connected a fiat conductored cable 28 which passes through thechamber 20 in engagement with the several circuit cards 21. Alsodisposed within the chamber 20 is a flat conductored cable 30, the freeend of which is connected to an appro priate electronic component.Between the cables 28 and 30 is disposed a tension strap 32, the lowerend of which is connected to a tension spring 34. A pair of guiderollers 36 maintain the cables 28 and 30 and the strap 32 in therelationship illustrated. Tension may be exerted on the strap 32 bymeans of a cam 38 having a handle 40. A guide bar 42 is provided for thestrap 32. The tensioning of the strap 32 is etfected after movement ofthe module 16 to the position illustrated in FIG. 2. To assure properalignment of the module 16, guide rollers 44 are provided in the housing12. If desired, the module 16 may form a door for the opening 14, itbeing important in this connection only that the edges 18a of thecircuit cards 18 are brought to the position shown in FIG. 2.

In FIG. 4 is illustrated a fragmentary plan view of a typical circuitcard. The card illustrated has a plurality of spaced parallel conductors46 and is provided with a pair of guide pins 48 which are received inalignment holes along the marginal edges of the cables 28 and 30. By thearrangement illustrated, compressive forces are exerted between thecables 28 and 30 and the edge contacts of the circuit cards 18 and 21,when the cam 38 is actuated to exert tension on the tension strap 32.

By the above arrangement, the conductors of the cables 28 and 30 may beas little as .010 to .10" wide with relatively great effectiveness ofelectrical interconnection due to the relatively high compressivecontact resultant forces of the tension force exerted. It will be notedthe contacts are positive and direct. There is little likelihood ofabrasion from engagement or disengagement. The circuit cards 18 and 21may bisect the angularly offset rows of conductive paths at anintersector angle up to 80". Assuming a 60 pound tensile, a lateralresultant compressive cable contact force of approximately 17.36 poundsis exerted against the contact edges of the circuit cards. It will beappreciated that the interleaved relationship of the circuit cards 18and 21 is important to attain the desired resultant forces.

The contacts 50 are engaged by either the cable 28 or the cable 30. Theobverse side of the strip 49 may be arranged to connect the contacts 50with other and ditferent conductors. In fact, the strip 49 constitutes aprogrammer which may be replaced at will.

In FIG. a is illustrated a modified form of programmed modified strip49a. In this form of the invention the edge contacts 502: are in asingle row and, since there are no alignment holes, alignment may beeiiected by arranging the components in operative relationship on a cardguide track.

In FIG. 6 is illustrated a modified form of the invention in which acircuit card 18a is brought into the illustrated coplanar position withrespect to the fixed circuit card 21a. The circuit card 18a comprises aplurality of conductored layers 54, 56 and 58 separated by dielectriclayers 60 and 62. The layer 54 has conductors 64 provided with adownturn end portion 66 while the layer 58 has a conductor 68 formedwith a downturn portion 70. The layers 56, 60 and 62are recessed to forma cavity 72. The circuit card 21a comprises conductored layers 74, 76and 78 spaced by dielectric layers 80 and 82. The layer 76 extendsbeyond the plane of the other layers and has conductors 84 with downturnportions 86. Disposed between the confronting circuit cards areconductored cables 28 and 30 tensioned by the tension strap 32. Becauseof the compressive forces generated, the conductored sections 66 arebrought into mating engagement with the conductors of the cable 30 whilethe conductor portions 86 are brought into mating engagement with theconductors on the cable 28. A series of circuit cards 18a and 21a may bestacked in limited space relation. It will be appreciated that thecircuit cards 18 and 21 may also be disposed in limited spaced relation.

The requisite tension may be supplied by the use of a heat-shrinkablestrip of material such as polyvinyl, or the like. Shrinking may beeffected by irradiation or by conventional electrical resistance, or byany other heat source.

I claim:

1. An electrical connector comprising a housing having an opening, meansfor mounting a first series of spaced circuit cards within said housing,means for mounting a second series of spaced circuit cards in saidhousing in partially interleaved relation to said first series, saidfirst series and said second series being movable in parallelismrelative to each other, a pair of flat conductored cables adapted to bereceived in said housing in a tortuous path defined by the electricalcontact edges of the circuit cards of said first series and said secondseries, and tension means for biasing said cables into conductiverelation to the circuit cards of said first series and said secondseries.

2. An electrical connector in accordance with claim 1 wherein saidtension means is interposed between said cables.

3. An electrical connector in accordance with claim 2 wherein saidtension means comprises a tension strap resiliently connected to saidhousing.

4. An electrical connector in accordance with claim 3 wherein means areprovided for exerting a tension force on said tension strap.

5. An electrical connector in accordance with claim 3 wherein saidtension exerting means includes a cam, or the like.

6. An electrical connector in accordance with claim 1 wherein thecircuit cards of said second series are removably mounted in spacedrelation in a module so that all of the circuit cards of said secondseries may be brought into interleaved relation with respect to thecards of said first series.

7. An electrical connector in accordance with claim 1 wherein each ofsaid circuit cards comprises a plurality of conductors spaced by one ormore dielectric layers, which may support and interconnect individualcomponents and, or, electronic micro-circuits.

8. An electrical connector in accordance with claim 1 wherein guidemeans are provided to align said conductored cables with respect to saidcircuit cards.

9. An electrical connector in accordance with claim 7 wherein contactmodifier strips are interposed between the edges of at least some ofsaid circuit cards and the associated conductored cable.

10. An electrical connector in accordance with claim 9 wherein at leastsome of said contact modifier strips comprise a single row of contacts.

11. An electrical connector in accordance with claim 9 wherein at leastsome of said contact modifier strips are provided with a series oflongitudinally spaced contacts at each marginal edge thereof.

5 6 12. An electrical connector in accordance with claim 1 ROBERT K.SCHAEFER, Primary Examiner wherein said tension means comprises aheat-shrunk strip. L SCOTT Assistant Examiner References Cited U S C1 XRUNITED STATES PATENTS 5 339-17 3,169,214 2/1965 Whitelmrn. 3,348,10210/1967 Bosland et a1. 317-112

